Hunting as a source of alien species: a European review

Invasive alien species (IAS) have been identified as one of the most important direct drivers of biodiversity loss, ecosystem degradation and ecosystem service changes. The threats posed by IAS have consequently been addressed through the development of many international policy instruments, guidelines and technical tools. In this context, understanding the pathways of species introductions constitutes a key issue as regards managing and preventing further invasive events. The most common motivation for the introduction of plant and animal species into new areas has by far been the establishment of new food sources. In Europe, hunting is a social and cultural activity in which millions of people are involved as both participants and beneficiaries, and it is undertaken on millions of hectares of land and wetland. Hunting activities are responsible for the translocation and restocking of millions of animals throughout Europe, including the introduction of alien species. In a context of the growing use of game translocations and of increasing concern about the impact of biological invasions, our goal is to review the role of alien species introduced primarily for hunting purposes on the European scale. We explored, among other aspects, the relative importance of game species in the context of alien species introductions and the underlying human demographic factors driving the diversity of introduced game species per country. We reviewed several lists of species that had been introduced into Europe, which we obtained from either scientific papers, books and technical reports. or official databases such as the Global Invasive Species Database (‘‘GISD’’), and Delivering Alien Invasive Species Inventories for Europe (‘‘DAISIE’’). We defined ‘‘introduced game species’’ as those introduced species that are deliberately sought and legally harvested from the wild, whether for sport, individual consumption, or commercial harvest. Our study showed that 24.3% of the mammals and 30.2% of the birds introduced into Europe during the last century were released primarily for hunting purposes, in total, 93 species (63 birds and 36 mammals). The most important taxa is Artiodactyls, Anseriformes and Galliformes. The species composition differed among countries, with a higher diversity of introduced game species in larger countries and in those with a higher human population density and proportion of hunters. This review stresses that hunting was a significant pathway for the introduction of invasive species into Europe in the last century. Since some of the game species introduced have had severe environmental impacts on many European regions, and introductions of non-native game species are still occurring, it is essential to improve regulations and increase public awareness regarding invasive game animals. This will help to preserve biodiversity and improve the sustainability of current hunting schemes in increasingly managed European ecosystems.peerReviewe